Initial observations on using magnesium metal in peripheral nerve repair.

Biodegradable magnesium metal filaments placed inside biodegradable nerve conduits might provide the physical guidance support needed to improve the rate and extent of regeneration of peripheral nerves across injury gaps. In this study, we examined basic issues of magnesium metal resorption and biocompatibility by repairing sub-critical size gap injuries (6 mm) in one sciatic nerve of 24 adult male Lewis rats. Separated nerve stumps were connected with poly(caprolactone) nerve conduits, with and without magnesium filaments (0.25 mm diameter, 10 mm length), with two different conduit filler substances (saline and keratin hydrogel). At 6 weeks after implantation, magnesium degradation was examined by micro-computed tomography and histological analyses. Magnesium degradation was significantly greater when the conduits were filled with an acidic keratin hydrogel than with saline (p < 0.05). But magnesium filaments in some animals remained intact for 6 weeks. Using histological and immunocytochemical analyses, good biocompatibility of the magnesium implants was observed at 6 weeks, as shown by good development of regenerating nerve mini-fascicles and only mild inflammation in tissues even after complete degradation of the magnesium. Nerve regeneration was not interrupted by complete magnesium degradation. An initial functional evaluation, determination of size recovery of the gastrocnemius muscle, showed a slight improvement due to magnesium with the saline but not the keratin filler, compared with respective control conduits without magnesium. These results suggest that magnesium filament implants have the potential to improve repair of injured peripheral nerve defects in this rodent model.

Immunogenicity of a recombinant human immunodeficiency virus (HIV)-canarypox vaccine in HIV-seronegative Ugandan volunteers: results of the HIV Network for Prevention Trials 007 Vaccine Study.

In the first preventative human immunodeficiency virus (HIV) vaccine study to be carried out in Africa, 40 HIV-seronegative Ugandan volunteers were randomly assigned to receive a canarypox vector containing HIV-1 clade B (env and gag-pro) antigens (ALVAC-HIV; n = 20), control vector containing the rabies virus glycoprotein G gene (n = 10), or saline placebo (n = 10). Cytotoxic T lymphocyte activity against target cells expressing clade A, B, and D antigens was assessed using standard chromium-release and confirmatory interferon-gamma enzyme-linked immunospot (ELISPOT) assays. Neutralizing antibody responses to cell line-adapted strains and primary isolates in all 3 clades were also tested. Twenty percent of vaccine recipients generated detectable cytolytic responses to either Gag or Env, and 45% had vaccine-induced HIV-specific CD8(+) T cell responses, as measured by the ELISPOT assay. In contrast, only 5% of the control group had vaccine-specific responses. Neutralizing antibodies against primary and laboratory-adapted HIV-1 clade B strains were seen in 10% and 15% of vaccine recipients, respectively, but responses against clades A and D were not detected. Although the immunogenicity of this clade B-based vaccine was low, ALVAC-HIV elicited CD8(+) T cell responses with detectable cross-activity against clade A and D antigens in a significant proportion of vaccine recipients.

Duration of efficacy of treatment of latent tuberculosis infection in HIV-infected adults.

BACKGROUND: Treatment of latent infection is needed to protect HIV-infected individuals against tuberculosis. A previous report addressed short-term efficacy of three regimens in HIV-infected adults. We now report on long-term efficacy of the study regimens. METHODS: Three daily self-administered regimens were compared in a randomized placebo-controlled trial in 2736 purified protein derivative (PPD)-positive and anergic HIV-infected adults. PPD-positive subjects were treated with isoniazid (INH) for 6 months (6H), INH plus rifampicin for 3 months (3HR), INH plus rifampicin and pyrazinamide for 3 months (3HRZ), or placebo for 6 months. Anergic subjects were randomized to 6H or placebo. RESULTS: 6H initially protected against tuberculosis in PPD-positive individuals; however, benefit was lost within the first year of treatment. Sustained benefit was observed in persons receiving 3HR and 3HRZ. In a Cox regression analysis, the adjusted relative risk for tuberculosis compared with placebo was 0.67 [95% confidence interval (CI), 0.42-1.07] for 6H, 0.49 (95% CI, 0.29-0.82) for 3HR, and 0.41 (95% CI, 0.22-0.76) for 3HRZ. When the rifampicin-containing regimens were combined, the adjusted relative risk for tuberculosis compared with placebo was 0.46 (95% CI, 0.29-0.71). Among anergic subjects, a modest degree of protection with 6H was present (adjusted relative risk, 0.61; 95% CI, 0.32-1.16). Treatment of latent tuberculosis infection had no effect on mortality. CONCLUSION: Six months of INH provided short-term protection against tuberculosis in PPD-positive HIV-infected adults. Three month regimens including INH plus rifampicin or INH, rifampicin and pyrazinamide provided sustained protection for up to 3 years.

Use of the neodymium: YAG laser for interstitial cystitis: a prospective study.

PURPOSE: Interstitial cystitis is a disorder of the bladder characterized by urgency and frequency of urination, and pelvic pain. The classic type of interstitial cystitis is characterized by Hunner's ulcers, which are focal regions of severe bladder inflammation. Patients with Hunner's ulcers tend to have more severe symptoms and are often refractory to medical management. We present a prospective series of patients who underwent ablative therapy of Hunner's ulcers using a neodymium (Nd):YAG laser. MATERIALS AND METHODS: A total of 24 patients with interstitial cystitis underwent ablative therapy for Hunner's ulcers. Medical therapy had failed in all cases. Using regional or general anesthesia the Nd:YAG laser under cystoscopic control was used to ablate the ulcers. The power setting was 15 W. with a firing duration of between 1 and 3 seconds. The procedure was performed on an outpatient basis. Symptoms were noted preoperatively and postoperatively. RESULTS: All patients had symptom improvement within 2 to 3 days. The mean pain scores decreased from 9.1 to 1.2 (p <0.003), the mean urgency score decreased from 8.2 to 1.9 (p <0.003), the mean voiding interval increased from every 30 minutes to every 102 (p <0.0001) and nocturia decreased from a mean of 7.9 voids per night to 2.9 (p <0.0001). There were no complications. Mean followup was 23 months. However, relapse in 11 patients required 1 to 4 additional treatments. The re-treatment response was similar to the initial treatment. CONCLUSIONS: Nd:YAG laser ablation of Hunner's ulcers is an excellent, minimally invasive method of treating interstitial cystitis. While it is not a cure, it offers patients an opportunity to have decreased symptoms for an extended period and it may be repeated as necessary.

Quantification of tumor cell injury in vitro and in vivo using expression of green fluorescent protein under the control of the GADD153 promoter.

The GADD153 gene is strongly transcriptionally activated by many types of cellular injury and the magnitude of the change in GADD153 expression is proportional to the extent of damage. We developed a novel reporter system in which a chimeric gene containing the GADD153 promoter linked to the coding region of an enhanced green fluorescent protein (EGFP) gene was stably integrated into the genome of a clone of UMSCC10b head and neck carcinoma cells. Activation of the exogenous GADD153 promoter was quantified using flow cytometric measurement of EGFP expression following drug exposure. The exogenous GADD153 promoter in this clone was activated by N-methl-N'-nitro-N-nitrosoguanidine (MNNG) in a concentration-dependent manner with kinetics that closely paralleled perturbation of cell cycle phase distribution. EGFP expression was strongly activated by a variety of genotoxic agents including DNA cross-linking and methylating agents, oxygen free radicals, DNA intercalator, UV and gamma-radiation and hypoxia. When grown as a xenograft in nude mice, the stably transfected clone also demonstrated dose-dependent EGFP expression when measured 4 days after cisplatin treatment. The reporter system accurately categorized the relative potency of adducts produced by 6 related platinum-containing drugs. In conclusion, this reporter system can facilitate in vitro and in vivo screening for agents capable of producing cytotoxicity via a wide variety of different mechanisms, and can be utilized to investigate the relative potency of structurally related DNA adducts.

Impact of tuberculosis (TB) on HIV-1 activity in dually infected patients.

Active TB in HIV-1-infected subjects is associated with increased HIV-1-related immunodeficiency and mortality. We assessed plasma viral load in HIV-1-infected patients with pulmonary TB (HIV/TB) and non-TB symptomatic HIV-1-infected patients (HIV). HIV-1 load was higher in HIV/TB compared with HIV at higher CD4 counts (> 500/microl) (P < 0.01), but not at lower CD4 counts (< 500/microl). We also evaluated the status of HIV-1 gene expression in peripheral blood mononuclear cells (PBMC) and serum from HIV/TB and CD4-matched healthy HIV-infected patients (HIV/C) by reverse transcriptase-polymerase chain reaction over a range of CD4 (> 900/microl to < 200/microl). HIV-1 RNA in serum and PBMC correlated to one another, and both were markedly higher in HIV/TB compared with HIV/C with higher CD4 counts. Also, during a longitudinal study of anti-tuberculous chemoprophylaxis in HIV-1-infected patients, 10 subjects who developed TB had serologies before, at the time, and after the diagnosis of TB. These HIV/TB patients had an increase in viral load (average 2.5-fold) at the time of diagnosis of TB (P < 0.05). Overall, these data indicate that the transcriptional activity of HIV-1 is enhanced in HIV-1-infected patients with active TB, especially during early HIV-1 disease. As TB often is an early HIV-1 opportunistic infection, it may particularly favour early viral replication and dissemination, and therefore contribute to progression of HIV-1 disease.

HIV-1 ICD p24 antigen detection in ugandan infants: use in early diagnosis of infection and as a marker of disease progression.

The objective of this study was to determine the use of immune-complex dissociated (ICD) p24 antigen detection for the diagnosis and prognosis of HIV-1 infection in Ugandan children. Plasma collected prospectively from children born to HIV-1 infected Ugandan women was stored and later analyzed for the presence of neutralizable HIV-1 p24 antigen using the Coulter ICD p24 antigen and neutralization kits. HIV-1 infection status, disease progression, and survival of the children were determined. Specimens from 311 children born to HIV-1 infected women, including 138 HIV-1 infected children, and 113 children born to negative women were tested. Sixty-nine (50%) infected children were p24 antigen positive at least once. For early HIV-1 diagnosis, the specificity and positive predictive value of the assay were consistently high (>95% and >83% respectively), but the sensitivity was low (6-53%), especially in the first months of life. The presence of p24 antigenemia in the first two years of life was associated with poor survival (20%) by 80 months of age compared with infected children without antigenemia (43%, P < 0.001). Early detection of p24 antigen (6 months, P < 0.001). The data suggest that ICD p24 antigen detection is not a sensitive method for the determination of infant HIV-1 status in our cohort of HIV-1 infected Ugandan children tested in the first two years of life. There was a strong correlation, however, between the presence and time of onset of p24 antigenemia and mortality among HIV-1 infected children.

Efficacy of an unsupervised 8-month rifampicin-containing regimen for the treatment of pulmonary tuberculosis in HIV-infected adults. Uganda-Case Western Reserve University Research Collaboration.

SETTING: National Tuberculosis Treatment Centre, Mulago Hospital, Kampala, Uganda. OBJECTIVE: To assess the efficacy of a daily, self-administered 8-month rifampicin-containing regimen for the treatment of pulmonary tuberculosis (TB) in human immunodeficiency virus (HIV) infected adults. DESIGN: Treatment outcomes in patients with pulmonary TB treated with a single 8-month regimen and followed in a prospective epidemiological study. RESULTS: Two hundred and sixty-five HIV-infected and 26 non-HIV-infected adults with initial episodes of pulmonary tuberculosis were treated with 2 months of daily isoniazid (INH), rifampicin (RMP), ethambutol and pyrazinamide followed by 6 months of daily INH + RMP. Median follow-up was 17.8 months. Ninety-five per cent of the HIV-infected and all of the non-HIV-infected patients who had sputum examined were sputum culture negative after 2 months of treatment. Twenty-two HIV-infected and no non-HIV-infected patients died during treatment. Relapse rates were 8.4% (5.9 per 100 person-years of observation [PYO], 95%CI 3.2-8.6) among HIV-infected patients and 4.5% (2.1/100 PYO, 95%CI 0-7.8) for non-HIV-infected patients. Adverse drug reactions occurred in 37% of the HIV-infected patients; most were minor and self-limiting. CONCLUSION: An 8-month RMP-containing regimen was well tolerated and effective in the treatment of HIV-infected adults with initial episodes of pulmonary TB. Relapse rates were similar to those reported with 6-month short-course regimens in HIV-infected individuals. Decisions about the duration of anti-tuberculosis treatment for HIV-infected adults must balance programme resources and the likelihood of poor compliance with longer regimens with the potential for a modest decrease in relapses with longer treatment.

A new era of discovery in facial plastic surgery.

OBJECTIVE: To review recent advances in our understanding of molecular biology and wound healing relevant to facial plastic surgery. DATA SOURCES: Recent basic science literature relevant to molecular biology and wound healing and its clinical implications. CONCLUSIONS: During the 21st century, we will experience a new biological and informational age that will have profound implications for facial plastic surgery. This modern era will be driven by discoveries in molecular biology and wound healing that will result in new diagnosis and treatment modalities.

The effects of conjugated deferoxamine in porcine skin flaps.

BACKGROUND: The free radical scavenger, deferoxamine (DFO) has been shown to reduce skin flap necrosis; however, its shortcomings are its toxicity and short plasma half-life. METHODS: This study investigates the effects of the less toxic, longer acting conjugated form, DFO-Hespan (DFO-H), to ischemic porcine skin flaps. During the study, DFO-H plasma concentrations and flap viability were evaluated over 10 days. RESULTS: Steady DFO serum levels were maintained with no evidence of systemic side effects. However, DFO-H was not effective in increasing porcine skin flap viability. Mean treated flap viability (n = 18) was 36.2% +/- 1.7% (mean +/- SE ) vs control (n = 16) 35.8% +/- 2.6%, p =.9. CONCLUSION: DFO-H conjugation increases its half-life and its systemic tolerance for DFO. However, this conjugation may also reduce DFO's effectiveness to preserve flap survival probably by decreasing its ability to reach the intracellular oxygen free radicals. In addition, further studies are needed to investigate whether longer DFO administration given postoperatively can be more effective in reducing ischemic injury.

Impact of pulmonary tuberculosis on survival of HIV-infected adults: a prospective epidemiologic study in Uganda.

BACKGROUND: Retrospective cohort studies of tuberculosis suggest that active tuberculosis accelerates the progression of HIV infection. The validity of these findings has been questioned because of their retrospective design, diverse study populations, variable compliance with anti-tuberculous therapy and use of anti-retroviral medication. To assess the impact of tuberculosis on survival in HIV infection we performed a prospective study among HIV-infected Ugandan adults with and without tuberculosis. METHODS: In a prospective cohort study, 230 patients with HIV-associated tuberculosis and 442 HIV-infected subjects without tuberculosis were followed for a mean duration of 19 months for survival. To assess changes in viral load over 1 year, 20 pairs of tuberculosis cases and controls were selected and matched according to baseline CD4 lymphocyte count, age, sex and tuberculin skin test status. RESULTS: During the follow-up period, 63 out of of 230 tuberculosis cases (28%) died compared with 85 out of 442 controls (19%), with a crude risk ratio of 1.4 [95% confidence interval (CI), 1.07-1.87]. Most deaths occurred in patients with CD4 lymphocyte counts < 200 x 10(6) cells/l at baseline (n = 99) and occurred with similar frequency in the tuberculosis cases (46%) and the controls (44%). When the CD4 lymphocyte count was > 200 x 10(6)/l, however, the relative risk of death in HIV-associated tuberculosis was 2.1 (95% CI, 1.27-3.62) compared with subjects without tuberculosis. For subjects with a CD4 lymphocyte count > 200 x 10(6)/l, the 1-year survival proportion was slightly lower in the cases than in the controls (0.91 versus 0.96), but by 2 years the survival proportion was significantly lower in the cases than in the controls (0.84 versus 0.91; P < 0.02; log-rank test). For subjects with a CD4 lymphocyte count of 200 x 10(6) cells/l or fewer, the survival proportion at 1 year for the controls was lower than cases (0.59 versus 0.64), but this difference was not statistically significant (P = 0.53; logrank test). After adjusting for age, sex, tuberculin skin test status, CD4 lymphocyte count, and history of HIV-related infections, the overall relative hazard for death associated with tuberculosis was 1.81 (95% CI, 1.24-2.65). In a nested Cox regression model, the relative hazard for death was 3.0 (95% CI, 1.62-5.63) for subjects with CD4 lymphocyte counts > 200 x 10(6)/l and 1.5 (95% CI, 0.99-2.40) for subjects with a CD4 lymphocyte count of 200 x 10(6)/l or fewer. CONCLUSION: The findings from this prospective study indicate that active tuberculosis exerts its greatest effect on survival in the early stages of HIV infection, when there is a reserve capacity of the host immune response. These observations provide a theoretical basis for the treatment of latent tuberculous infection in HIV-infected persons.

Vascular and epidermal effects of fibroblast growth factor on irradiated and nonirradiated skin flaps.

Head and neck cancer surgeons are often faced with the challenge of managing previously irradiated soft tissue that has poor vascularity and slower epithelialization. This study investigates the effect of supplemental basic fibroblast growth factor (bFGF) on flap vascularity, tissue oxygenation, and epidermal regeneration in nonirradiated (n = 40) and irradiated porcine skin flaps (n = 40). Supplemental bFGF increased vascularity in nonirradiated flaps by 80% (p = .005), with a trend to a higher tissue oxygen level by day 14. The irradiated bFGF-treated flaps did not show increased vascularity or higher tissue oxygen levels 2 weeks after surgery. However, in both irradiated and nonirradiated groups, epidermal regeneration increased by greater than 70% with supplemental bFGF (p < .002). The results of this study suggest that supplemental bFGF can increase tissue vascularity in nonirradiated tissues and epidermal regeneration in both nonirradiated and irradiated conditions.

Randomized controlled trial of Mycobacterium vaccae immunotherapy in non-human immunodeficiency virus-infected ugandan adults with newly diagnosed pulmonary tuberculosis. The Uganda-Case Western Reserve University Research Collaboration.

Adjunctive immunotherapy with heat-killed Mycobacterium vaccae was studied in a randomized, placebo-controlled trial of 120 non-human immunodeficiency virus-infected adults with newly diagnosed pulmonary tuberculosis. Patients were randomized to a single dose of M. vaccae or placebo 1 week after beginning chemotherapy and were followed up for 1 year. M. vaccae was safe and well tolerated. The rate of sputum culture conversion after 1 month of tuberculosis treatment was 35% in the M. vaccae group and only 14% in the placebo group (P=.01) but was comparable at 2 months and thereafter. Patients receiving M. vaccae had greater improvement on chest radiography at 6 months (91% vs. 77% for placebo recipients; P=.04) and 12 months (94% vs. 80%; P=.04) after initiation of tuberculosis treatment. These data provide evidence of an early increase in sputum culture conversion and greater radiographic improvement among patients who received M. vaccae. Further studies are warranted.

The role of nitric oxide in obstructive nephropathy.

PURPOSE: Ureteral obstruction leads to tubulointerstitial fibrosis and loss of renal function. Nitric oxide production ameliorates fibrosis due to obstructive uropathy. However, nitric oxide is produced by 3 isoforms of the enzyme, nitric oxide synthase. We evaluated the role of inducible nitric oxide synthase in obstructive uropathy using nitric oxide synthase knockout mice, and determined whether the administration of L-arginine to promote nitric oxide synthesis by alternative nitric oxide synthase isoforms modulates renal fibrosis in these animals. MATERIALS AND METHODS: Complete unilateral ureteral obstruction was created in wild-type C57 and inducible nitric oxide synthase knockout mice. Control animals of each strain underwent sham surgery. Throughout the experiment mice had free access to untreated tap water or water supplemented with 10 gm./l. L-arginine. Animals were sacrificed 1 and 2 weeks, respectively, after creation of unilateral ureteral obstruction. We obtained serum as well as bladder and obstructed renal pelvic urine, and determined the nitrite level in each fluid. Renal cortical thickness was measured in the normal and obstructed kidneys. The degree of tubulointerstitial fibrosis was evaluated by trichrome staining and type I collagen deposition in kidney tissue specimens. RESULTS: Nitrite was significantly decreased in the serum, bladder and renal pelvic urine of inducible nitric oxide synthase knockout mice with unilateral ureteral obstruction compared with that in wild-type C57 mice at 1 and 2 weeks (p<0.05). In knockout mice with unilateral ureteral obstruction 1 week in duration that drank tap or L-arginine supplemented water nitrite in serum and each urine sample was higher than in sham operated knockout controls. The level returned to baseline after 2 weeks of obstruction (p<0.05). After 2 weeks of obstruction there was significantly greater cortical thinning in knockout than in C57 mice (p<0.05). Moreover, knockout mice given L-arginine supplemented water for 2 weeks had even greater cortical thinning than after 1 week or than mice given tap water for 1 to 2 weeks (p<0.05). Decreased renal cortical thickness in knockout mice after 2 weeks of obstruction was associated with less intense trichrome staining and a virtual absence of type I collagen deposition compared with findings in the wild-type C57 strain. CONCLUSIONS: Inducible nitric oxide synthase knockout mice with unilateral ureteral obstruction have significantly lower nitrite in serum and urine than wild-type C57 mice. Knockout mice also have more severe renal cortical thinning than C57 animals after creation of unilateral ureteral obstruction. Providing L-arginine supplemented water to inducible nitric oxide synthase knockout mice exacerbates the loss of cortical thickness. Alterations in cortical thinning that we observed in knockout mice were associated with decreased tubulointerstitial fibrosis and a decreased net renal extracellular matrix accumulation. These data indicate that endothelial or neuronal nitric oxide synthase may be more important than inducible nitric oxide synthase for modulating renal fibrosis in obstructive uropathy.

Choosing the optimal wound dressing for irradiated soft tissue wounds.

This article reviews the healing state of the previously irradiated wound, the tenets for optimal wound care, and the choices of wound dressings now available for its management. The goal in assisting a previously irradiated surgical wound to heal is to transform its chronic wound state into an acute wound state. This transformation encourages wound healing to proceed. Six major moisture-retentive dressing categories exist to optimize its healing. They are classified into the alginates, foams, gauzes, hydrogels, hydrocolloids, and transparent films. Optimal wound care management for previously irradiated wounds involves (1) adequately debriding and cleansing the local wound, (2) accurately assessing the wound, (3) choosing the appropriate dressing based on the wound assessment, and (4) encouraging granulation tissue formation and reepithelialization.

Ibuprofen combined with antibiotics suppresses renal scarring due to ascending pyelonephritis in rats.

PURPOSE: In acute pyelonephritis renal scarring may be decreased by immediate antibiotic therapy. Unfortunately in children there is often a delay in starting treatment, which increases the likelihood of renal scarring. In rodents immediate antibiotic therapy is effective for preventing renal scar formation resulting from experimentally induced pyelonephritis. However, the same treatment beginning 72 hours after infection does not prevent renal scarring in this paradigm. We examined whether delayed administration of the nonsteroidal anti-inflammatory agent ibuprofen only or combined with antibiotics suppresses renal scarring in a model of ascending pyelonephritis in rats. MATERIALS AND METHODS: An inoculum of 5x10(9) organisms per ml. of Escherichia coli strain BH-5 was instilled into the bladder of rats and the urethra was occluded for 4 hours. Groups of animals were and were not treated with 15 mg./kg. cefadroxil or 10 mg./kg. ibuprofen given twice daily for 5 days, or the 2 drugs combined. Treatment began 72 hours after inoculation. In an additional group of rats sterile phosphate buffered saline was instilled into the bladder. In each rat the kidneys were examined grossly and microscopically 6 weeks later. RESULTS: Combined antibiotics and ibuprofen significantly inhibited gross renal scarring compared with no treatment or antibiotics only (p<0.05). No difference in renal scarring was detected in animals that received no treatment versus those that received antibiotics or ibuprofen only (p>0.05). CONCLUSIONS: Renal scarring resulting from acute pyelonephritis in this rat model is not decreased by delayed treatment with antibiotics only. The addition of ibuprofen to antibiotic therapy is effective for decreasing renal scarring due to acute pyelonephritis even when treatment is delayed for 72 hours.

Thyroid gland hematoma after blunt cervical trauma.

Thyroid hematoma is a rare cause of airway obstruction in victims of blunt trauma. The case of a 34-year-old woman who developed orthopnea after a low-energy motor vehicle accident is described. Presenting greater than 24 hours after her accident, the patient noted dysphagia, tracheal deviation, and postural dyspnea. The diagnosis of thyroid gland hematoma was made with a combination of fiberoptic laryngoscopy, cervical computed tomography, and great vessel and carotid angiography. Invasive airway management was not required. The patient underwent a total thyroidectomy and recovered without complications.